What is the introduction of female characters in plays attributed to?

The introduction of female characters in plays is attributed to Thespis of Icaria, a 6th-century BCE Greek actor and playwright. Before Thespis, all roles in Greek plays were played by male actors, who would often wear masks to represent female characters. Thespis is credited with being the first actor to take on the role of a female character without wearing a mask and to introduce dialogue between male and female characters on stage. This innovation in playwriting has been seen as a major breakthrough in the development of Greek theatre and drama.